The present invention relates to a method for segregating qualities of an agricultural product during processing of the product. The invention also relates to a measuring instrument for analyzing the quality of an agricultural product. The measuring instrument is arranged on an implement for treatment of the product.
In agricultural industry, it is today common knowledge that the price of an agricultural product is decided by the percentage of the constituents of the product. When a transaction is to be agreed upon, a sample of the product is analyzed to decide the quality.
Today, several methods exist for deciding the constituents in an agricultural product. The product could be analyzed by wet-chemical methods or by spectroscopy. The latter is more easily performed and considerably faster and is therefore often preferred. A grain marketer, to whom the farmer sells his products, usually performs the analysis when the transaction is made and different loads of the product are then segregated by quality. The farmer will therefore not know the quality of his product until he sells it.
Naturally, the farmer would like to produce products of the finest quality, so that he can charge the highest possible price for his products. The farmer would therefore like to have some kind of control of the quality of his products.
In U.S. Pat. No. 5,991,025 an apparatus is disclosed for analyzing grain as it is being harvested by a combine. Thus, the combine carries a reflectance spectrometer for analyzing the major constituents of the grain in real time as it is being harvested. A similar apparatus is disclosed in U.S. Pat. No. 6,100,526. These apparatuses give the farmer an opportunity to easily get a map of the quality of his product in different places of his field. Thus, the field could be divided into different parts that give different qualities of the product. It is intended that the farmer should use the information of the quality differences in order to treat different parts of the field differently. The field does not have homogeneous external conditions, e.g. the received sunlight and the moisture of the soil could vary in the field, and therefore different parts of the field should be treated differently in order to give the same quality. These apparatuses can help the farmer to map a field and to cultivate each part optimally in order for the product to be equally good in different parts of the field under different external conditions.
However, it takes a long time until the farmer gets a better quality of his grain. Using these apparatuses he can learn how his field should be cultivated and it will take years of experience until he knows how to produce the best possible quality.
Further, U.S. Pat. No. 5,991,025 and U.S. Pat. No. 6,100,526 disclose apparatuses that use reflectance measurements on product samples as the products flow past a measurement position. Thus, the product samples are irradiated and reflected light is detected. This implies that light that has been reflected from the surface of the individual particles gives the largest contribution to the detected light. The measurements might then give an incorrect result of the determined amounts of the constituents in the sample. For example, the harvested product could be covered by dew, which would lead to a determined value of the water content in the product that is higher than the actual value. In the case of e.g. barley or oats, the product is covered by a hull, which will lead to problems in correctly determining the protein content of the product, since the hull and the core of the particles are not equally composed.
It is an object of the invention to enable a process operator to control the quality of an agricultural product that is delivered from the process. It is another object of the invention to enable a farmer to control the quality of a product that is harvested. It is another object of the invention to enable a farmer to charge the highest possible price for his products.
The object of the invention are achieved by a method as described below.
Thus, the invention provides a method for segregating qualities of an agricultural product during processing of the product. The method comprises the step of setting a desired range of a measurement value, which represents a property of the product. The measurement value defines a first quality of the product for which the measurement value is inside the range and a second quality of the product for which the measurement value is outside the range. The method further comprises the step of analyzing the quality of the product that is being processed. The step of analyzing comprises the steps of continuously extracting samples of the product, irradiating each sample by electromagnetic radiation, spatially separating electromagnetic radiation of different wavelengths, and detecting electromagnetic radiation emitted from the sample. The step of detecting produces intensity signals indicative of detected electromagnetic radiation of different wavelengths. The step of analyzing further comprises the steps of determining a sample value of said property of the product from the intensity signals and determining a measurement value from at least one sample value. The method further comprises the step of separating the product of said first quality from the product of said second quality.
Thanks to the invention, a process operator can set a desired quality of the agricultural product. By analyzing the quality of the product as it is being processed, the method can ensure that different qualities of the product are not mixed. In this way, if a farmer has different qualities in different parts of his field, the different qualities will not be mixed during harvesting. When the product has been harvested from the field, the farmer could have two or more loads of products of different qualities. He will then be able to charge a high price for the product of fine quality, instead of charging a common, lower price for the product of both qualities.
In the context of this application, an agricultural product is a cultivated product, such as grain, soya beans, or corn. The measurement value, which represents a property of the product, could represent any property that is directly measurable or derivable from a measurement by a spectrometric method. For example, the measurement value could represent a percentage of a constituent, such as protein or moisture, in the product.
The continuous extracting of samples of the product implies that samples are extracted during the whole process. The extracting of samples could be made at varying intervals and need not be made in immediate succession to each other.
The detection of electromagnetic radiation emitted from the sample implies that the radiation, which enters the product sample, could be e.g. reflected, transmitted or scattered in the sample before it is detected.
According to a preferred embodiment, the measurement value is an integrated value of several successively determined sample values. Thus, a mean value of the sample values, representing a property of the product, could be measured and continuously updated. Then, the mean value could be controlled for the product that has passed the measurement. If the mean value is changing and becoming close to a boundary of the desired range, the product that have passed the measurement could be separated from the product being measured upon, in order to keep different qualities segregated.
According to another embodiment, only the latest sample value is considered for determining the measurement value. Thus, the quality of the product presently being processed could be controlled. The desired range could be set for controlling that no product with a sample value outside the range is mixed with the product with a sample value inside the range. This could be used for controlling the standard deviation of the property of the product within a load.
A preferred method further comprises the step of returning the product sample to normal processing of the product after the analysis. In this way, no product is lost in the analysis.
According to another preferred embodiment, the method further comprises the step of holding the product sample fixated during the steps of irradiating and detecting. As a result, the measurement conditions could easily be repeated for all samples. Thus, the result of the measurement will not vary due to a differing flow of the sample. This implies that the measurement results are reliable. Also, when detecting radiation that has been transmitted through the sample, the detector should not be directly irradiated by the radiation source. Therefore, it is suitable that the sample is fixated, since the risk of pinholes in the sample that could let radiation through directly to the detector is reduced. Further, the distance that the radiation passes through the sample should be held essentially the same. This could be more easily achieved if the sample is fixated during measurement.
Preferably, the method further comprises the step of compressing the product sample during the steps of irradiating and detecting. As a result, vibrations in the surroundings of the measurement position will not affect the product sample. Since the measurement is performed during processing of the product, such vibrations are frequently occurring. Thus, the compression of the sample will attenuate the vibrations and give reliable sample values.
Preferably, the step of detecting comprises detecting electromagnetic radiation that has been transmitted through the sample. As a result, all parts of particles in the sample will contribute equally to the detected radiation. This implies that a correct result can be acquired even if the particles are heterogeneous, i.e. if the constituents are not equally distributed throughout the particles.
According to yet another preferred embodiment, wavelengths of the radiated electromagnetic radiation are in the near infrared range. These wavelengths are particularly suitable for analysis of constituents in an agricultural product, since the absorption for these wavelengths is highly dependent on the contents of the product. Furthermore, the transmittance of the radiation through the agricultural products is relatively high for these wavelengths, which implies that the irradiation intensity can be relatively low.
Preferably, the product is being harvested by means of a combine and the steps of analyzing and separating are performed on the combine. This implies that a farmer could control the quality of his product during harvesting of the product.
Preferably, the method further comprises the step of passing the harvested product into a container on the combine. Thus, the product that has been harvested is collected on the combine.
According to a preferred embodiment, the method further comprises the step of emptying the container when the determined measurement value is of a different quality from the harvested product in the container. As soon as the product that is being harvested is no longer of the same quality as the harvested product in the container, there is a risk of mixing two differing qualities of the product. Thus, the container on the combine is emptied when this occurs. The container could be emptied into another container on a vehicle that follows the combine. This vehicle may have several containers for different product qualities. The product of the new quality could then be filled into the container on the combine without the risk of mixing the differing qualities.
Alternatively, several vehicles could follow the combine for collecting products of different qualities. The combine could have a signaling system for informing an operator of the following vehicle which container the product should be emptied into. This signaling system could be implemented as two or more lamps on top of the combine. The combine operator will turn on the lamp corresponding to the quality that is to be emptied.
As a further alternative, the combine comprises several containers. Then, the method further comprises the step of altering the passing of the product to a first container on the combine to passing the product to a second container on the combine, when the determined value of a sample is of a different quality from the harvested product in the first container. This is a different way of preventing the risk of mixing different qualities of the harvested product.
The step of extracting a sample preferably comprises extracting a product sample from a product elevator on the combine. As a result, no mechanical feeding of the product sample to the measuring position and back to the ordinary flow of products on the combine is needed. The sample could simply fall into the measuring position and then fall back onto a lower part of the product elevator on the combine.
The objects of the invention are also achieved by a measuring instrument for use in the method. The measuring instrument comprises a radiation source for irradiating a sample with electromagnetic radiation, a wavelength separator for spatially separating the electromagnetic radiation of different wavelengths, and a detector for detecting electromagnetic radiation emitted from the sample. The detector produces intensity signals indicative of detected electromagnetic radiation of different wavelengths. The measuring instrument further comprises an analyzer for analyzing the intensity signals and determining the value of at least one property of the product.
The objects of the invention are further achieved by a method for analyzing the quality of an agricultural product during processing of the product. The method comprises the steps of extracting a sample of the product, feeding the sample to a measurement position, compressing the sample in the measurement position, irradiating the sample by electromagnetic radiation, spatially separating electromagnetic radiation of different wavelengths, and detecting electromagnetic radiation emitted from the sample. The step of detecting produces intensity signals indicative of detected electromagnetic radiation of different wavelengths. The method further comprises the step of determining a measurement value from the intensity signals, which value represents a property of the product.
Thus, an improved method for analyzing a product during processing is achieved. Since the product sample is compressed in the measurement position, vibrations and movements in the surroundings of the measurement position do not affect the sample. This implies that the result of the measurement is reliable. Thus, the quality of the product could be decided with certainty during the processing of the product. As a result, decisions on how to treat the product could be taken during the processing. For example, a segregation of different qualities of the product could be provided during the processing of the product.
The objects of the invention are also achieved by a measuring instrument for analyzing the quality of an agricultural product. The measuring instrument is arranged on an implement for treatment of the product, thus enabling analysis of the product during the treatment of the product in the implement. The measuring instrument comprises a measurement unit for measuring at least one property of the product. The measurement unit comprises a sample holder, which is arranged to hold a product sample fixated during analysis, and a radiation source, which is arranged to irradiate a product sample in the sample holder with electromagnetic radiation. The measurement unit further comprises a wavelength separator for spatially separating electromagnetic radiation of different wavelengths, and a detector for detecting electromagnetic radiation that has been transmitted through a product sample in the sample holder. The detector produces intensity signals indicative of detected electromagnetic radiation of different wavelengths. The measuring instrument further comprises an analyzer for analyzing the intensity signals and determining a value of the at least one property of the product, and a sample feeding unit, which is arranged to feed a product sample from a process on the implement to the sample holder in the measurement unit.
Thanks to the measuring instrument, the quality of the product that is being treated can continuously be controlled. This implies that the measuring instrument provides a possibility of observing when the quality of the product changes.
Since the detector detects transmitted electromagnetic radiation, the radiation passes through all parts of a particle before it is detected. This implies that if the particles in a product sample are heterogeneous, i.e. if they have different properties in the surface than in the core, this will be accounted for. Furthermore, since the sample is fixated during analysis, the thickness of the samples could easily be held constant. This also implies that the risk of pinholes decreases, i.e. holes through the sample, through which the radiation could pass unaffected from the radiation source to the detector.
According to a preferred embodiment, the measurement unit is detachably connectable to the implement for treatment of the product. This implies that the measurement unit could be disconnected from the implement. Thus, the measurement unit could be used for measurement on products that are not being treated on the implement. A farmer could use the measurement unit disconnected when he is at the farm and connected when he is harvesting.
The measuring instrument preferably comprises an indicator, which indicates when a measured property of the product is outside a range. The indicator can give an operator of the implement an instant signal, when the quality of the product does not meet the desired requirements. This helps the operator to make sure that different qualities are not mixed.
Suitably, the range is adjustable. The operator can thus set a desired quality of the product that he wants to keep unmixed from other qualities of the product. For example, different kinds of products will need different desired qualities.
Preferably, the implement for treatment of the product is a combine. Thus, the quality of the product could be controlled while the product is harvested. This implies that the product of one quality will be separated from the product of another quality as soon as it is harvested.
The electromagnetic radiation is preferably transmitted an adjustable distance in the product sample between the radiation source and the detector. This is useful if different kinds of products are to be analyzed. Different products have different optical densities and therefore the amount of detected radiation will be different if the distance the radiation travels through the sample is not adjustable. The adjustment of the distance can set the levels of detected radiation to be approximately equal for different kinds of products and thus the same detector could be used.
Preferably, the sample holder comprises a shaft, which provides a cavity for containing the product sample during analysis. The cavity can then be filled by the sample and hold the sample fixated during analysis.
Suitably, the sample holder comprises an inlet for feeding a product sample from the sample feeding unit to the shaft and an outlet for returning the product sample to the sample feeding unit. As a result, the sample holder could easily be connected to a flow of products in the sample feeding unit for receiving product samples.
According to a preferred embodiment, the sample holder further comprises shutters for controlling the feed of product samples to and from the shaft. Thus, the shutters could open and shut the inlet and the outlet to control the flow of products through the shaft.
Preferably, a distance between the walls of the shaft is adjustable. This implies that a sample thickness, i.e. the distance that the radiation travels through the product sample could be adjusted for different kinds of products.
Alternatively, the radiation source is moveable relative to the detector in a direction of propagation of the irradiated electromagnetic radiation. Thus, the distance between the detector and the radiation source could be varied for different kinds of products. In this alternative, the radiation source is suitably partly inside the cavity. Consequently, the adjusted distance between the detector and the radiation source adjusts the sample thickness.
As another alternative, the shaft of the sample holder is replaceable. Thus, a shaft with a thickness suited for the kind of product, which is to be measured, could be installed in the measurement unit before measurement. When another kind of product is to be measured, the shaft is simply replaced.
According to another preferred embodiment, the shaft is moveable from a first position for receiving a product sample from the inlet to a second position for irradiation of the product sample and further moveable to a third position for returning the product sample to the outlet. This implies that the flow of particles to and from the shaft could easily be controlled. Thus, a product sample that is being analyzed will not be filled with more products through the inlet.
Preferably, the walls of the shaft are constructed of a transparent material for letting the electromagnetic radiation through to the product sample. Thus, the radiation source and the detector can be arranged outside the shaft without the shaft affecting the electromagnetic radiation.
Suitably, the cavity is smaller in the second position than in the first position. This implies that the sample is compressed when it is analyzed. This diminishes the risk of pinholes and movements in the sample during the analysis.
According to one embodiment, the shaft is transversely moveable relative to the inlet and the outlet. This is a simple design of the shaft. The sample could easily be compressed in the second position where it is analyzed.
According to another embodiment, the shaft is rotatingly moveable. This is a simple movement of the shaft, since the movement will not have to be altered for returning the cavity from the third position to the first position.
Preferably, a radius of a wall surrounding the rotating shaft decreases from the first position to the second position. This implies that the sample will be compressed, while the shaft is rotated from the first position to the second position.
According to a preferred embodiment, the shaft comprises a wheel with at least two paddles that extend radially from a rotational axis of the shaft movement. The paddles form a sector between them, which sector constitutes a cavity for holding a product sample and guiding the product sample along the shaft movement. This embodiment of the shaft will lead samples in the rotational movement. The paddles will guide the samples in the movement while providing a cavity for defining the size of a sample.
Preferably, the sector is essentially cone-shaped. This means that the cavity does not have a uniform thickness in cross section. Thus, different sample thicknesses could be provided for different kinds of products.
In a preferred embodiment, the radiation source and the detector are radially moveable relative to the rotational axis. If the cavity is cone-shaped, the sample thickness that is analyzed will depend on the placement of the radiation source and the detector. Thus, the sample thickness that is being measured upon could easily be adjusted.
In another embodiment, the cross-section of a sector at a radial distance from the rotational axis has a varying thickness. This implies that the sample thickness in the second position will vary when the sector is rotated past the second position. As a result, the sample thickness that is measured upon could easily be varied.
In another preferred embodiment, the wheel comprises permanent cells having different thicknesses. This implies that a cell with a thickness that is suited for a product could be used for the measurement on the product.
According to another embodiment, the wheel comprises several sectors for holding product samples. In this way, a sample could be collected from the inlet in one sector, while another sample is analyzed in another sector. This gives a possibility of analyzing samples at a high frequency.
Preferably, the wheel is rotatable in a first direction for analysis of the product sample and in a second, opposite direction for recording a reference spectrum on an empty sector. When the wheel is rotated in the second direction, a sector could be brought from the third position to the second position without passing the first position. Thus, an empty sector could be presented to the radiation source and the detector. This means that a reference spectrum could very easily be recorded, while the measuring unit is arranged on the combine.
According to one embodiment, the shaft is rotatingly moveable around a rotational axis that is perpendicular to the inlet and the outlet. This implies that it is simple to arrange a driving axle for propelling the shaft, since the driving axle will not interfere with the inlet or the outlet.
According to another embodiment, the shaft is rotatingly moveable around a rotational axis that is parallel to the inlet and the outlet. This implies that it is easy to empty a sector. It might even be possible to include a cleaning device for pushing the sample out of the sector.
The objects of the invention are further achieved by a measuring instrument for segregating qualities of an agricultural product during harvesting of the product, wherein the instrument is arranged on a combine for harvesting the product and comprises a measurement unit. The measurement unit comprises a radiation source for irradiating a product sample by electromagnetic radiation, a wavelength separator for spatially separating electromagnetic radiation of different wavelengths, and a detector for detecting electromagnetic radiation emitted from the product sample. The detector produces intensity signals indicative of detected electromagnetic radiation of different wavelengths. The instrument further comprises a sample feeding unit for extracting a sample of the product from the combine and feeding the product sample to the measurement unit, and an analyzer for determining a value of a property of the product sample based on the intensity signals. Values of said property within a range represents a first quality and values of said property outside said range represents a second quality. The analyzer is arranged to indicate a change in quality of the product that is being harvested, whereby the product of said first quality is separable from the product of said second quality.